Recent bone quantitative ultrasound approaches exploit the multimode waveguide response of long bones for assessing properties such as cortical thickness and stiffness. Clinical applications remain, however, challenging, as the impact of soft tissue on guided waves characteristics is not fully understood yet. In particular, it must be clarified whether soft tissue must be incorporated in wavegu...

Most ultrasonic guided wave methods require tone burst excitations to achieve some degree of mode purity. In addition, it is often desirable to acquire data using multiple frequencies, particularly during method development when the best frequency for a specific application is not known. However, this process is inconvenient and time-consuming, particularly if extensive signal averaging at each...

Numerical simulation based on finite element method is conducted to predict the location of pitting corrosion in reinforced concrete. Simulation results show that it is feasible to predict corrosion monitoring based on ultrasonic guided wave in reinforced concrete, and wavelet analysis can be used for the extremely weak signal of guided waves due to energy leaking into concrete. The characteris...

A methodology for the predictive modeling of smart structures with in-situ sensing capability is presented and discussed. First, the smart structures concept is briefly reviewed. Then, self-sensing smart structures with in-situ sensing capabilities are introduced. Focus is placed on active sensing methods using ultrasonic guided waves in thin-wall structures. The challenges of modeling ultrason...

The inspection of industrial tubes such as those present in heat exchangers or boilers for defects using established methods generally requires careful cleaning of the tubes. This is time consuming and as a result cost-intensive. A fast screening tool based on ultrasonic guided wave technology, which minimizes the need for cleaning, is presented. A specially designed ultrasonic probe to excite ...

The rainbow trapping effect has been demonstrated in electromagnetic and acoustic waves. In this study, rainbow trapping of ultrasonic guided waves is achieved in chirped phononic crystal plates that spatially modulate the dispersion, group velocity, and stopband. The rainbow trapping is related to the progressively slowing group velocity, and the extremely low group velocity near the lower bou...

In order to quantify the wave motion of guided ultrasonic waves, the characteristics of piezoelectric detectors, or ultrasonic transducers and acoustic emission sensors, have been evaluated systematically. Such guided waves are widely used in structural health monitoring and nondestructive evaluation, but methods of calibrating piezoelectric detectors have been inadequate. This study relied on ...